Valproic Acid Use in Pregnancy Tied to Malformation Risk

In addition to spina bifida,
first-trimester use tied to higher odds of five congenital malformations

By Lindsey Marcellin

HealthDay Reporter

THURSDAY, June 10 (HealthDay News) -- In pregnant women, first-trimester use of valproic acid is associated with significantly increased risks of five congenital malformations in addition to spina bifida, according to research published in the June 10 issue of the New England Journal of Medicine.

Janneke Jentik, of the University of Groningen in the Netherlands, and colleagues combined data from eight cohort studies in which pregnant women were exposed to valproic acid, and then performed a case-control study using a large European antiepileptic-study database. Cases were defined as certain congenital malformations after the mother had been exposed to valproic acid monotherapy during the first trimester. Two control groups were utilized in the study; group one comprised infants with malformations other than those under study and whose mothers did not use an antiepileptic drug in the first trimester, and group two comprised infants whose malformations were known to be due to chromosomal abnormalities.

Of the 180 registrations of women who were exposed to valproic acid monotherapy during pregnancy, 122 were cases, 45 were in control group one, and 13 were in control group two. Comparing cases to group one, the researchers found that cases had a significantly increased risk of six of 14 malformations considered: spina bifida (odds ratio [OR], 12.7), craniosynostosis (OR, 6.8), cleft palate (OR, 5.2), hypospadias (OR, 4.8), atrial septal defect (OR, 2.5), and polydactyly (OR, 2.2). When exposure to valproic acid was compared with exposure to other antiepileptic drugs during early pregnancy, results were similar.

"Our findings provide further support for the recommendation of the American Academy of Neurology to avoid the use of valproic acid, if possible, in pregnant women," the authors write.

GlaxoSmithKline partially provided funding for another study during which the antiepileptic-study database was constructed, but was not involved in this study. Two of the authors disclosed that their registry received funding from GlaxoSmithKline.